Research On Key Technology Of Four-channel Tunable Filter Based On RF MEMS Switch

Filter is a kind of electronic components that can filter stray or useless signals and frequency selection.It is an indispensable basic component of a communication system.With the rapid development of communication systems,traditional bandpass filters can no longer meet the needs of miniaturization,high integration,and complex multi-band communication systems.The tunable filter can effectively solve the problem of large volume,and has attracted more and more attention in the field of radio frequency devices.Radio frequency MEMS switches have the advantages of low loss,small size,high linearity,easy integration,low power consumption,etc.Therefore,tunable filters based on radio frequency MEMS switches have become one of the current research hotspots.In this paper,through the integrated design of radio frequency MEMS switch and comb line filter,the radio frequency performance and manufacturing process of tunable filter are studied,and a four-channel tunable filter based on radio frequency MEMS switch is designed and manufactured.On the basis of summarizing the research and development status of tunable filters at domestic and international,the paper designs the overall structure of tunable filters from the design theory of band-pass filters.And then designs the upper electrodes and contacts of radio frequency MEMS switches,the resonant structure and input and output structure of the filter are analyzed and designed as well.The electromagnetic simulation software HFSS is used to simulate and optimize the switch,filter and tunable filter.Finally the specific structural parameters of a four-channel tunable filter is obtained.The paper studies the manufacturing process of a four-channel tunable filter based on radio frequency MEMS switches,introduces the manufacturing process of the tunable filter and the design of the layout of the tunable filter,and explains the specific manufacturing process steps and key points,so that the sample of four-channel tunable filter based on radio frequency MEMS switch were obtained.Finally,a test method for the tunable filter is proposed,and the developed tunable filter samples are tested.